1. Field of the Invention
The present invention relates to a vehicle motion control apparatus cooperatively using a plurality of control objects.
2. Description of Related Art
JP-B-4297150 describes a vehicle in which when an oversteer (hereinafter referred to as ‘OS’) state or an understeer (hereinafter referred to as ‘US’) state of a vehicle occurs, the distribution of driving force to respective front and rear wheels is first changed, if the oversteer or understeer state still progresses further, then a steering angle is corrected, and if the oversteer or understeer state still progresses further, then selective braking is performed on a selected wheel.
JP-B-4455379 describes a vehicle US suppressing apparatus in which as an increase in the amount of US, reactive force suppressing control by an electric power steering device (hereinafter referred to as ‘EPS’), alarming by an alarm device, and distributing of braking forces to respective wheels are performed sequentially in this order.
However, the vehicle described in JP-B-4297150 merely determines the control device used to perform the control operations and the order thereof in order to suppress the OS state or US state. Further, the vehicle US suppressing apparatus described in JP-B-4455379 merely sequentially operates a plurality of control objects to supplement the amount of control in a stepwise manner in order to realize a required control value to suppress US. That is, although JP-B-4297150 and JP-B-4455379 describe that the lateral motion of a vehicle is controlled in combination with the plurality of control objects, they do not consider e.g. which control object should be operated with high priority based on the controllable ranges (availability) of respective control devices in order to perform a more optimal control. For example, when the control amount, which is an item of the availability, is different according to the control objects, determining the control object with reference to only the control amount cannot realize well-responsive control output if fast control response e.g. in emergency is required. Thus, it is preferred to perform an optimal control to the vehicle motion using a plurality of control objects.
In the meantime, while the lateral motion of a vehicle has been described in the above, the forward and backward motion and pitching motion of a vehicle may also be applied.